Process of producing ferric phosphates.



PUCESS Uh PMUJDUGING- FERN PHUSPH IME 11 WILLIAM H. nnnnir, db DETRUJHIZ, lllllUHl ld-hlil',

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tions of ferric phosphates, the result being surfaces of basic phosphates on such articles and the changing of the ferric phosphates in it solution to inactive ferrous phosphates, and the object of this invention is to provide a novel my be changed to ferric phosphates while in solution.

The patent to Richards No. 1,069,903, dated August 12, 1913, suggests the use of manganese dioxid in the rust-proofing of iron and steel and it has been found that the value of this material lies in the fact 25 that it converts the feus ferric phosphates. llt is an oxling out, but is expensive and objectionable in that it constitutes an inconvenient seent in the WBt-PJI'OOL! bath.

lln the rust-proof: of articles of iron and steel, the bath is usually prepared by ac a upon iron or steel with a hotone half per cent. solution of phohoric acid The checal reaction continues until a point of saturation is reached, that is, until the foras. Att'this point, the solut on is no longer edeetive for the production of the desired fcrro phospw a.

specification of letters fatent.

process whereby ferrous phosphates phosphates to,

mation of insoluble ferrous phosphates be ldatend duly application filed deptemberthilliu. rial Ito. ltitltt,

This solution, after it has settled and become clear, may have a ely' divid current of air blown up through it. [lr the solution may be permitted to trickle down through a chamber through which a current of air is ascending. Ur the solution may be caused to flow in a very thin sheet over flat plates while currents of air pass over it. In

each case, because of the comparatively large surface exposed to the air, the acid ferrous phosphates absorb oxyen and form acid ferric phosphates, some the more insoluble being precipitated. If the solution were evaporated the deposited salt will not rated. 7

The solution of acid ferric phosphates is intensely active as a rust-roofing agent.

lee-brought in contact with currents of air..-

l, 'lhe process of convertin ferrous phosphates in the presence of phosphoric acid in" aqueous solution to ferric which consists in s stantially eyery part of. the same into contact with dill,

' 2. The process of convert ferrous phosphates in the presence of phosphoric acid in aqueous solution to ferric phosphates which consists in J I a: finely divided cents of air throng solution.

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redissolve in the amount of water evapolid hit

Illphosphates 

